TELEFUNKEN EL84-TK Vacuum Tube Single

Product overview

The TELEFUNKEN EL84-TK Vacuum Tube Single is the Black Diamond Series EL84, a power pentode and a replacement for any EL84 / 6BQ5 tube, supplied here as a single EL84-TK tube.

TELEFUNKEN describes the EL84-TK as a perfect replacement for any EL84 / 6BQ5, offering reliable performance and a great sound. It is a thermionic valve of the power pentode type, originally designed for the output stages of audio frequency amplifiers, and it can deliver up to 17 watts.

Output, up to	17 W
Also known as	6BQ5
Tube in this product	1
Treated, tested and burned‑in	Cryogenic

Key features

• EL84 / 6BQ5 power pentode
• Delivers up to 17 watts
• Compact: physically smaller than most common output tubes
• Chiming, articulate sound when overdriven
• For the output stages of audio frequency amplifiers
• Black Diamond Series: rigorously tested, cryogenically treated and extensively burned-in

The EL84-TK sound

Although it is physically smaller than most common output tubes, this pentode can really deliver. In many ways it is similar to the EL34 without the output horsepower. Like its EL34 cousin, the EL84 is found in many British amplifiers, and when overdriven it produces a distinctive chiming and articulate sound.

One tube, two names

EL84 is the European designation and 6BQ5 the American one, so the EL84-TK goes into any output socket specified for either.

Applications

• Two-tube combo amplifier: compact combos with a pair of EL84 output tubes
• Four-tube combo amplifier: combos and heads with four EL84 output tubes
• Hi-fi amplifier output stage: audio frequency amplifiers with EL84 / 6BQ5 output stages
• Studio backline: studios keeping their EL84 amplifiers ready for chiming overdriven tones
• Live sound and touring spares: backline techs carrying replacement output tubes
• Rental inventory: rental stores retubing amplifiers between bookings

Black Diamond Series

TELEFUNKEN Elektroakustik Black Diamond Series vacuum tubes are new production tubes, manufactured in partnership with a specialist vacuum tube factory in Slovakia and designed to be harmonically rich and tonally balanced. Each tube is rigorously tested, cryogenically treated and extensively burned-in before it carries the Black Diamond name, so the EL84-TK arrives ready for the most demanding applications.

This configuration: Single

This product is one EL84-TK tube, sold singly.

Fitting and care

Always switch the equipment off, unplug it from the mains and let the tubes cool completely before removing or fitting a tube. Fit the EL84-TK only in a socket specified for the EL84 or 6BQ5, keep each tube in the position of the one it replaces, and press it straight and fully into the socket. Power sections hold high voltages, so leave any work inside the chassis, including any bias adjustment the amplifier requires, to a qualified technician. After fitting, let the equipment warm up and listen at low volume first. Store spare tubes in their packaging, protected from knocks and moisture.

What's included

Included	One TELEFUNKEN EL84‑TK vacuum tube
Not included	Amplifier or equipment, sockets and installation, bias adjustment

In the box

• One TELEFUNKEN EL84-TK vacuum tube

Vacuum tubes are glass components: handle them by the glass envelope, avoid knocks and keep them in their packaging until fitting.

TELEFUNKEN EL84-TK Vacuum Tube Single: frequently asked questions

Is the EL84-TK the same as a 6BQ5?

Yes. TELEFUNKEN offers the EL84-TK as a replacement for any EL84 / 6BQ5 tube.

How much power can an EL84 deliver?

TELEFUNKEN states that the EL84 can deliver up to 17 watts.

What does Black Diamond Series mean?

It is TELEFUNKEN Elektroakustik's range of new production vacuum tubes, designed to be harmonically rich and tonally balanced; each tube is rigorously tested, cryogenically treated and extensively burned-in.

Do I need a technician to fit it?

Fitting is a straight swap in the socket, but power sections and rectifier circuits hold high voltages. Where an amplifier has adjustable bias, have a qualified technician check it after fitting new power tubes, following the amplifier maker's instructions.

How many tubes are included?

One tube, sold singly.

Where can I buy the TELEFUNKEN EL84-TK Vacuum Tube Single in India?

The TELEFUNKEN EL84-TK Vacuum Tube Single is available from Shivansh Electronics, Kolkata, West Bengal, India, with delivery across India.

Workflow 1: Two-tube combo amplifier

Compact combos with a pair of EL84 output tubes.

Connections

Connect	To
EL84‑TK	The two EL84 output sockets

Setup

1. Switch the amplifier off, unplug it from the mains and let the tubes cool completely; power sections hold high voltages, so leave work inside the chassis to a qualified technician.
2. Note each position, then gently rock the old EL84 tubes straight out of their sockets.
3. Fit the EL84-TK tubes with the pins or key aligned, pressing each fully home, and refit any retainers.
4. Power up and let the amplifier warm up; have the bias checked by a qualified technician where the amplifier requires it, then check the sound at low volume.

Tip: A single tube replaces one position.

Workflow 2: Four-tube combo amplifier

Combos and heads with four EL84 output tubes.

Connections

Connect	To
EL84‑TK	The four EL84 output sockets

Setup

1. Switch the amplifier off, unplug it from the mains and let the tubes cool completely; power sections hold high voltages, so leave work inside the chassis to a qualified technician.
2. Note each position, then gently rock the old EL84 tubes straight out of their sockets.
3. Fit the EL84-TK tubes with the pins or key aligned, pressing each fully home, and refit any retainers.
4. Power up and let the amplifier warm up; have the bias checked by a qualified technician where the amplifier requires it, then check the sound at low volume.

Workflow 3: Hi-fi amplifier output stage

Audio frequency amplifiers with EL84 / 6BQ5 output stages.

Connections

Connect	To
EL84‑TK	EL84 / 6BQ5 output sockets of the hi‑fi amplifier

Setup

1. Switch the amplifier off, unplug it from the mains and let the tubes cool completely; power sections hold high voltages, so leave work inside the chassis to a qualified technician.
2. Note each position, then gently rock the old EL84 tubes straight out of their sockets.
3. Fit the EL84-TK tubes with the pins or key aligned, pressing each fully home, and refit any retainers.
4. Power up and let the amplifier warm up; have the bias checked by a qualified technician where the amplifier requires it, then check the sound at low volume.

Workflow 4: Studio backline

Studios keeping their EL84 amplifiers ready for chiming overdriven tones.

Connections

Connect	To
EL84‑TK	EL84 output sockets of the studio amplifier

Setup

1. Switch the amplifier off, unplug it from the mains and let the tubes cool completely; power sections hold high voltages, so leave work inside the chassis to a qualified technician.
2. Note each position, then gently rock the old EL84 tubes straight out of their sockets.
3. Fit the EL84-TK tubes with the pins or key aligned, pressing each fully home, and refit any retainers.
4. Power up and let the amplifier warm up; have the bias checked by a qualified technician where the amplifier requires it, then check the sound at low volume.

Workflow 5: Live sound and touring spares

Backline techs carrying replacement output tubes.

Connections

Connect	To
EL84‑TK	Spares case, then the EL84 sockets of the touring amplifier

Setup

1. Switch the amplifier off, unplug it from the mains and let the tubes cool completely; power sections hold high voltages, so leave work inside the chassis to a qualified technician.
2. Note each position, then gently rock the old EL84 tubes straight out of their sockets.
3. Fit the EL84-TK tubes with the pins or key aligned, pressing each fully home, and refit any retainers.
4. Power up and let the amplifier warm up; have the bias checked by a qualified technician where the amplifier requires it, then check the sound at low volume.

Workflow 6: Rental inventory

Rental stores retubing amplifiers between bookings.

Connections

Connect	To
EL84‑TK	EL84 sockets of the rental amplifier

Setup

1. Switch the amplifier off, unplug it from the mains and let the tubes cool completely; power sections hold high voltages, so leave work inside the chassis to a qualified technician.
2. Note each position, then gently rock the old EL84 tubes straight out of their sockets.
3. Fit the EL84-TK tubes with the pins or key aligned, pressing each fully home, and refit any retainers.
4. Power up and let the amplifier warm up; have the bias checked by a qualified technician where the amplifier requires it, then check the sound at low volume.